The present invention is directed to data networks and, more particularly, to wireless data networks for providing mobile terminals and other devices with high speed data services such as high speed Internet services.
Wireless data networks are typically employed as an extension of a wired data network or in place of a wired data network to provide user access to networked data services. The wireless data networks reduce or eliminate the need for wired connections and thus permit fast setup of a data network as well as allow for simplified, low cost additions to and reconfiguration of the data network. The wireless data networks also facilitate the use of hand-held or notebook computers, personal digital assistants (PDA) or other handheld or pocket devices to access the data services.
Presently, wireless data networks may be configured either as non-cellular wireless local area networks (LANs) or as cellular wireless data networks. Non-cellular wireless data networks, such as peer-to-peer wireless LANs or single or multiple access point wireless LANs, provide high data throughput and thus support high speed data services. However, the non-cellular wireless data networks do not permit a user's computer or other device to remain connected to the network when the computer or device is moved from within the communication range of one access point or peer device to within the range of another access point or peer device. Thus, non-cellular wireless data networks provide users with only limited mobility.
By contrast, cellular wireless data networks provide users with greater mobility. The cellular wireless data networks are divided into cells that function in a manner analogous to those of cellular mobile telephone network. At a given time, each computer or other device of the cellular wireless data network is associated with a respective access point and its corresponding cell or area of coverage. Communication between the computer or other device and the cellular wireless data network is “handed off” from one access point to another as the computer or other device roams from cell to cell. The cells overlap to permit continuous communication between the computer or other device and the cellular wireless data network. Thus, cellular wireless data networks extend the range that the computer or other device may be connected to the data network. Traditional cellular wireless data networks, however, have poor bandwidth efficiency, also known as spectral efficiency,
It is therefore desirable to provide a wireless data network that is capable of providing high speed data services as well as permitting high user mobility.